Field
The present disclosure generally relates to the design of a hybrid optical source. More specifically, the present disclosure relates to the design of a hybrid optical source with optical proximity coupling provided by an external reflector.
Related Art
Optical interconnects enabled by silicon photonics may be the ultimate solution to removing the inter-chip communication bottlenecks for high performance computing systems with numerous processor chips and memory chips. Compared with electrical interconnects, optical interconnects offer unmatched bandwidth, density, energy efficiency, latency, and reach. In particular, recently developed ultra-compact silicon photonic (SiPh) devices with low parasitics facilitate high-speed operation with low power consumption.
There has recently been considerable progress in developing a comprehensive portfolio of SiPh components for such optical links. A number of SiPh components have been developed, such as waveguide high-speed modulators and photodetectors, polarization controlling elements, and multi-port multiplexers, although a SiPh light source remains elusive. Note that silicon is a poor light emitter due to its indirect bandgap. However, well-studied III-V semiconductor counterparts provide a formidable material of choice to realize a SiPh light source, as long as a practical and efficient III-V material/semiconductor-on-insulator (SOI) hybridization solution is found. Note that III-V/SOI hybrid lasers are still lagging in technical maturity despite a flurry of development activity. Nonetheless, hybrid integration of III-V devices with silicon photonic circuitry provides a sensible design path, as both III-V-semiconductor-based and SOI-based structures can be optimized independently with their most advanced dedicated materials, processing and reliability screening technologies before integration and assembly.
However, a number of technical challenges must be overcome to produce a system that effectively integrates III-V-material structures and SOI-based structures. In particular, it is challenging to design a hybrid optical source that is both practical to manufacture, and can effectively communicate light beams between chips containing these two types of structures.
Hence, what is needed is hybrid optical source that overcomes these challenges and effectively integrates III-V semiconductor structures with SOI-based photonic circuitry.